Final answer:
Hamlet devises a plan to stage a play that mirrors the alleged murder of his father as told by the ghost. He uses the play as a means to watch King Claudius's reaction, which would serve to confirm or deny the ghost's accusation of regicide.
Step-by-step explanation:
Hamlet's plan for gaining proof of the ghost's tale involves staging a play that mimics the circumstances of his father's murder as described by the ghost. Through this play, Hamlet hopes to observe King Claudius's reaction to see if he exhibits any signs of guilt.
The idea is that if Claudius reacts strongly to the play, it would confirm the ghost's story and validate its claim that Claudius murdered Hamlet's father.
Hamlet instructs a group of actors to perform a play with a scene that closely resembles the method of murder that the ghost described.
During the performance, Hamlet and Horatio closely watch Claudius's behavior. This strategy demonstrates Hamlet's clever use of theatrical mimicry as a form of counter-espionage against his uncle, as well as his skepticism towards the supernatural claims made by the ghost.